The GF Eclipse Plugin provides an integrated development environment (IDE) for developing grammars in the Grammatical Framework (GF). Built on top of the Eclipse Platform, it aids grammar writing by providing instant syntax checking, semantic warnings and cross-reference resolution. Inline documentation and a library browser facilitate the use of existing resource libraries, and compilation and testing of grammars is greatly improved through single-click launch configurations and an in-built test case manager for running treebank regression tests. This IDE promotes grammar-based systems by making the tasks of writing grammars and using resource libraries more efficient, and provides powerful tools to reduce the barrier to entry to GF and encourage new users of the framework.